\begin{tikzpicture}
    \tkzDefPoints{0/0/O}
    \tkzDefPoint(200:1.5){A}
    \tkzDefPoint(340:1.5){B}
    \tkzDefPoint(90:1.5){M}
    \tkzDefLine[perpendicular=through M,normed](O,M)  \tkzGetPoint{c}
    \tkzDefPointOnLine[pos=1.5](M,c)  \tkzGetPoint{C}
    \tkzDefPointOnLine[pos=2.0](C,M)  \tkzGetPoint{D}

    \tkzDrawCircle[thick](O,A)
    \tkzDrawPoint(O)
    \tkzDrawPolygon(A,B,M)
    \tkzDrawSegments(C,D)
    \tkzLabelPoints[above](O)
    \tkzLabelPoints[left](A,C)
    \tkzLabelPoints[right](B,D)
    \tkzLabelPoints[above](M)
\end{tikzpicture}

